Indicating device



May' 23, 193.9.y w. E. NEWMAN 2,159,749

INDICATING DEVICE Filed Nov. 50, 1934 2 sheets-sheet 1 y 4%? Y 4^? F! IN1/Emme:

EN Mdm/Z ,ewmam May 23,1939. w. E. NEWMAN `INDICATING DEVICE Filed Nov. 30, 1934 2 Sheets-Sheet 2 `Patented May 23, 1939` PATENT OFFICE INDICATING DEVICE William E. Newman, Moorestown, N. J., assgnor, by mesne assignments, toRadio Corporation of America, New York, N. Y., a corporation of Delaware n Application November 30, 1934, Serial No. 755,337

8 Claims. (Cl. 11G-124.1)

My invention relates to improvements in tuning mechanismjfor radio receivers.

One of the objects of my invention is to provide I improved tuning mechanism of the character re- 1o1i operative movement of the various parts.

Il ferred to embodying a tuning element, such as a frequency to which the receiver is tuned, and

means for preventing back-lash between different elements of the connecting means for causing c- Another object of my invention is to provide improved tuning mechanism of the character referred to embodying a dial or other indicating element for showing the wave length or frequency to which the receiver is tuned, a Vernier dial or other equivalent element for indicating incre- `mental movements of the main dial, and means for preventing back-lash in the connecting means for causing cooperative movement `of the various I parts.

Another object of my invention is to provide `improved tuning mechanism of the character referred to which is particularly adaptable for an a correct indication of incremental movements of 'wall-wave radio receiver, which is provided with easily readable indicating means and which gives the gang condenser or other tuning element.

Another object of my invention is to provide Tiimproved tuning mechanism of the character reerred tonand wherein means are provided for i readily eiiecting a coarse or ne adjustment of the receiver.

Other objects and advantages will hereinafter n"appear. t t

In accordance with my invention, a pointer o1" n other indicating member is caused to move upon adjustment of the gang condenser or other tun- Ling element to give a relatively close indication 1'"of the wave length to which the receiver is tuned,

a Vernier pointer or other indicating member is between the gang condenser kof the receiver and .i two manually operable knobs, that rotation of one knob causes movement `of the condenser M'without the reduction effect of the differential device, while rotation of the other knob causes'rotation of the condenser through the differential device for relatively ne adjustment. y

My invention resides in the improved construction of the character hereinafter described and claimed.

For the purpose of illustrating my invention, an embodiment thereof is shown in the drawings, wherein Figure 1 is a front elevational view, partly broken away, of tuning mechanism constructed and operating in accordance with my invention, some of the parts being removed for the sake of clearness;

Fig. 2 is a sectional view, the section being taken on the line 2-2 in Fig. 1;

Fig. 3 is a sectional view, the section being taken on the line 3--3 in Fig. 2; n

Fig.` 4 is a sectional view, the section being taken on the line 4-4 of Fig. 2;

Fig. 5 is a sectional view, the section being taken on the line 5--5 in Fig. l;

Fig. 6 is a sectional View, the section being taken on the line 6-6 in Fig. 1;

Fig. '7 is a sectional view, the section being taken on theline 'l-'I in Fig. 5; and

Fig. 8 is a view similar to Fig. 2, showing a modification. n `l In the drawings, the` reference numeral I0 designates a gang condenser whose shaft I2 is rotatable through a given range of about 180".

For the purpose of rotating the shaft I2` tol make adjustments in tuning, a plate I4 is xed thereto. The edge-of .this plate is disposed between balls I6 held bya part I8 for free rotation or rolling movement, but against bodily move? ment. n

`The balls I6 are held pressed against the opposite sides of the plate I4 by the resilient sides 20 of a spool 22 which is fixed on a stubshaft 24.

The stubshaft 24 is rotated upon rotation of a hollow shaft 26 Xed thereto and provided with an operating knob 28. The hollow shaft 26 is provided with openings 30 in which balls 32 are disposed for free rotation. I

A ball race 34 is disposed about the shaft 26, as shown, and operates to hold the balls in position in the openings 30 and in an annular groove 36 in theend of a shaft 38. The ball race 34 is held against rotation by a xed element 40 whose end extends betweenspaced lugs 42 with which the race is provided.

The shaft 38 `is rotatable within the hollow shaft 26, and is provided with an operating knob 44.

For the purpose of making fine adjustments if the condenser, the knob 44 is rotatecltoeft'ect rotation of the balls 32, causing them to travel about the race 34 and rotate the shaft.' 2f and spool 22 at a reduced rate. By rotation'of the knob 44, therefore, the condenser shaft l2 is` rotated at a reduced rate not only by the balls I6 and associated parts, but through the differential device associated with the shafts 26 and 38.

To provi-de an indication of the angular position of the rotor of condenser I9, an indicating member 46 is fixed to the end of a spindle 48 coaxial with the condenser shaft I2 and extending outwardly from a part 50- fixed to the latter and which carries the plate I4. The member 46 is comprised of two pointers 52 and 54 extending in .diametrically opposite directions, and moves over a fixed dial 56v provided concentrically about its center and at different distances radially therefromv with the different scales A, B, C', D and X,

for the Various bands' over the entire frequency range for which the receiver is designed. From the foregoing, it will be understood that angular movement of the member 46 is the same as that :of the condenser shaft I2.

In changing from one band to another, a knob 51 is rotated to turna shaft 58 connected to a conventional wave-change switch (not shown). The particular band for which the receiver is set to operate is indicated by the position of an "elongated member 6U which has a sliding fit by it is always held against the lower edge of the slot 62. The member 68 is provided with desig nations corresponding, respectively, tofthose on l 4the dial` 56 for the different bands, and which are displayed through an opening 69 in the dial 56. In Fig. 1, the wave-change knob 51 is shown in the position for reception over the band D, in

.which case the reading for the'frequency to whichv the receiver is tuned is taken accordingtotheposition of the pointer 52 along the scale D. When the wave-change knob 51 is rotated in the clockwise direction to expose the designation X through the opening 69, the receiver will be set for reception over the band X. in which case the reading will be made according to the position of the pointer 54 with respect to the scale X. In the intermediate positions of the knob 51, the designations A, B and C will be displayed through the opening 69, to indicate to the operator the respective scale which is then to be used to indicate the wave length to which the receiver is tuned. Y

The entire dial 56 is illuminated uniformly by lamps 1l). Part of the light from the lamps 18 passes through translucent members` 12. -The rest of the light from these lamps is reflected from the miembers 12 to the face 14 of the casing 64, and is then reflected from this face to the dial 56.

Incremental movements of the member 46 are indicated by a second indicating member in the form of a Vernier pointer 16 which is xed on an extension 18 from a pinion 88 rotatable on the spindle 48. The p-ointer 16, upon rotation of the condenser shaft I2, is rotated through a gear train comprising a gear 82 fixed on the part 58, a pinion 84 rotatable on a stubshaft 86 fixed to the casing 64, and meshing with the gear 82, and a gear 88 fixed for rotation with the pinion 84 l "and meshing with the pinion 86. There is a substantial step-up ratio from the shaft I2 to the Vernier pointer 16, as will be seen, whereby an incremental movement of the pointer 46 is acwcompanied by` a substantial movement of the pointer 16. K

For the purpose of preventing back-lash in the geartrain, agear 90 is mounted for rotation on Y the stubs'haft 86, and meshes with the pinion 80.

This gear is similar and adjacent to the gear 88, andis provided with a hub 52 to which one end of a coil spring 94 is Xed.

The other end of this spring is fixed to the wall of a casing 96. The endl of the stubshaft 86 eX- tends through the center of the casing 96 and is riveted over asv shown to fix the latter against rotation.

. In assembling the parts, the pinion 80 is moved out of mesh with the gears 88 and 90, and the gear 98 is rotated in a clockwise direction, as viewed in Fig. 7, to wind up the spring 94 whereby the same is place in tension. The pinion 8D is then moved to the right, as viewed in Fig. 5, to place it in mesh with the gears' 88 and 96. The tension in the spring 94 is sufcient to rotate thevernier pointer 16, but is no-t great enough to disturb the setting of the condenser shaft I2. This is on account of the positive mechanical connection between the spool 22 and the condensershaft, at the reduction ratio.

The arrangement and relation of the pinions and gears comprising the gear drive is such that upon rotation of the condenser shaft I2 through its entire range of about 180, the Vernier pointer 16 rotates through a number of complete revolutions over the innermost scale on the dial 56. Furthermore, the respective dimensions and relation of the parts with respect to each other are such that for movement of the member 46 across any one division on the dial 56, the Vernier pointer 16 will move over a substantial number of divisions of its associated scale. For this reason, incremental movements of the member 46 can be easily read by reference to movement of the Vernier pointer 16 with respect to its scale.

'Ihe tension in the spring 94 operates at all times to urge the Vernier pointer 16 in a clockwise direction, as Viewed in Fig. 1. In this Way, contact is always maintained between the same respective sides of the teeth of the pinions and gears of the gear train during rotation of the condenser shaft I2 in either direction. Upon rotation of the condenser shaft I2 in the clockwiseV direction, looking toward the right in Fig. 5, the Vernier pointer 16 will be permitted to rotate in this direction under the action of the spring 94, the tension of which will then decrease correspondingly. Upon reverse rotation of the shaft I2, the Vernier pointer 16 will be rotated in the opposite direction by the positive mechanical connection provided by the gears and pinions of the gear train, at which time the spring 94 will be rewound to increase the tension therein,

i provided with an operating knob 44a for-making In the modification shown in Fig. 8, the shaft 98 corresponds to the shaft 24 in Fig. 2 `and `is relatively coarse adjustments of the condenser.

The `part 02 is fixed on the shaft L98, and correisponds to the part or hollow shaft 26`in Figi-2;`

` The shaft 93 extends loosely through `,a hollow shaft HB4 provided with an operating knob `28a rectly through the shaft 98 to the spool 22.

Erom the foregoing it will be seen that I have provided improved tuning mechanism for an allwave radio receiver in which Vernier indicating means are provided for vshowing incremental movements of the tuning element and in which `provision is made for preventing back-lash between the operating connections. HFurthermore, in my improved tuningmechanism,means are provided for readily making ,either relatively coarse or relatively fine adjustinents by the turning of selected knobs.

While but one modification of my invention has been disclosed, it will be understood that various modifications are possible without departing from the spirit of my invention or the scope of the claims.

, the latter to the former, and a tensioned spring having one end thereof fixed against movement V and its other end fixed for movement with one of the gears in said train to cause the spring tension to increase upon rotation of said shaft `in one direction and to cause the spring tension to decrease upon rotation of said shaft in the Opposite direction.

` y2. In tuning mechanism, a rotatable drive shaft having a given range of movement, means `.driven by said shaft for indicating the angular `position thereof, Vernier indicating means pro- `viding a visual indication of incremental move- ,ments of said first-named indicating means, tensioned spring means for driving said Vernier indicating means in one direction, connecting means between said shaft and said Vernier indicating means for driving the latter in the opposite direction and simultaneously increasing `the tension in said spring means upon rotation of said shaft in one direction, rotation of said shaft in the opposite direction operating through said connecting means to release said spring `means for the purpose set forth.

3. In combination, a rotatable indicating member, means comprising a gear-train for rotating said member, a gear similar to and supported ad- `Hiltionary with respect to each of the gears in said `.jacent one of the gears in said train for relative rotary movement with respect thereto and mesh- `ing with the same adjacent gear with which said second-named gear meshes, a tensioned coil spring associated with said first-named gear and train and to whiclrthe`- other end `of said spring is xed. whereby said spring is effective toprevent back-lash infsaid gear-train during rotation of said indicating member in` either direction.

4. ln'combination, a rotatable indicating member, ai'second indicating member supported adjacent to and for rotation about the axis of rotation of said first-named member, means for rotating` said first-named member, a gear-train connection between said means and said secondnamed member for rotating the latter at a greater rate than said first-named member, a gear meshed in said train and supported adjacent to one of the gears therein for rotation with respect thereto, a tensioned coil spring associated with said iirst-named gear and having one of its ends fixed thereto, and means fixing the other end of said spring against movement to hold the latter in tension whereby back-lash in said gear train is prevented.

5. In combination, a driving shaft, a driven shaft, an indicator on said driven shaft for indicating variations in the angular position of said driving shaft, a pinion on said driven shaft, means connecting said shafts and including at least two gears meshing with said pinion, means supporting said gears for independent rotation about a common axis, a `tensioned'spring connected to one only of said gears and operating by virtue of its tension to transmit torque through said gear and pinion to the said other gear, whereby to oppose rotation of said driven shaft when said driving shaft is rotated in one direction and to assist rotation of said driven shaft when said driving shaft is rotated in the other direction.

6. In apparatus of the character described, the combination of a dial having a plurality of concentrically arranged sets of arcuate scales and a circular scale displayed thereupon, a plurality of pointers arranged to turn about a common axis, one of said pointers being double-ended with its diametrically opposite end-parts registering with different scales of said sets of arcuate scales and a second of said pointers registering with said circular scale, driving means, speed-reducing transmission means connecting said driving means with said one of said pointers, and speedincreasing transmission means connecting said one of said pointers with said second of said pointers.

7. In apparatus of the character described, the combination of a dial having a plurality of differently graduated semi-circular scales and an evenly graduated circular scale displayed thereupon, said plurality of scales being concentrically arranged and representing different tuning wave bands and said circular scale spaced radially from said plurality of scales and representing fractional adjustments only, a plurality of pointers of different lengths arranged to turn upon a common axis, one of said pointers registering with said plurality of scales and a second of said pointers `registering with said circularscale, and driving means connected with said pointers to effect their simultaneous operation at relatively different speeds.

8. The combination, with the rotatable shaft of an adjustable radio tuning element, a driving shaft and transmission means connecting said shafts whereby one revolution of said driving shaft will effect a partial revolution of said rotatable shaft, of a dial having a plurality of dif- `ferently graduated semi-circular scales and an evenly graduated circular scale displayed thereupon, said plurality of scales being concentrically arrangedand representing different tuning Wave bands and said circular scale spaced from said plurality of scales and representing fractional adjustments only, a plurality of pointers o-f different lengths arranged to turn upon a common axis, one of said pointers registering With said plurality of scales and a second one of said pointers registering with said circular scale, and transmission means connecting said pointers with each other` and with said rotatable shaft whereby the operation of said driving shaft will effect the simultaneous movement of said pointers at relatively diierent speeds.

` Y WILLIAM E. NEWMAN. 

